Do I need a nmea multiplexer?

[Havana Shamrock]

Tried to intergrate my icom M504A to my E120 through NMEA 0183 but nothing I have an autopilot also, would i need to run everything through a multiplexer to get them to talk to each other? I want to make use of the DSC and AiS receiver functions.

 

[src]

I'm sure someone will correct me if I'm wrong, but with 0183 each source can have multiple listeners, but if you want a single listener to "hear" multiple sources then you need either an additional input (some of my devices have 2) or a multiplexer. So it really depends on how you want your devices to communicate. For more detail, we would need to know which devices should be receiving data from what.

 

[Alex F]

Joe,

I don't know what AP you have, but I would expect it to be tied to the E120 via SeaTalk (not NMEA0183), which is much faster. I would also assume that the new VHF might be integrated via SeaTalk. BTW, what does the installation manual recommends?

The bottom line is, before you start spending money on other components which might not be necessary I would focus on getting everything connected via SeaTalk.

Also, check if your boat is equipped with NMEA2000 Network switch.

Another note, don't hesitate to call the vendor's tech support line for suggestions on how the device should be connected. Between RM and iCom tech support you should be up and running in a short timeframe.

 

[Henry Boyd]

SRC summarized things pretty well. It sounds like you may need a multiplexer for a couple of reasons.

First nmea0183 runs at 4800 baud, AIS runs at 38400.

I'm not sure how many 0183 ports the e series have, nor do we know the GPS source for the DSC function on the VHF.

If you have the RM heading sensor, these use both a Seatalk connection and NMEA 0183 connection.

You may need a mux like the Actisense ndis 4 AIS. This would create a two way connection at 38400 with the e. The mux would take the NMEA inputs from the heading sensor, VHF and anything else as well as the AIS data. This would be bumped up to 38400 and fed to the e. The mux would also be set up with a NMEA output port at 4800 to feed GPS data back to the VHF. This port could be also used to feed something like SmartCraft .

The above is just a guess as to how it would work. The specifics depend on your actual hardware.

Henry

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[alnav]

You may already have a multiplexer although it's not called that. On my install of about the same vintage, Sea Ray used a Raymarine "Seatalk Converter" to connect the depth sensor and Smartcraft units to the E120s. It's essentially a multiplexer that can accept NMEA 0183 and Seatalk inputs and outputs both of those. It also has an RS232 port used to connect a PC.
If you have one of these it probably won't help you with the AIS connection as I don't think it can convert the higher baud rate. It might be possible to connect that directly to an unused port on one of your units, but I think you will have to get into the setup screens to let the unit know it need to use the higher baud rate.
If you do have a Seatalk Converter and still need another multiplexer you will have to take that into account for wiring that in to avoid conflicting signals. I had to do that to install a multiplexer with an internet connection. If your electronics were installed by Sea Ray, you can probably get an interface diagram from customer service, that's very nice to have for many reasons.

 

[Henry Boyd]

Another thing to check with the E is that if it does have two NMEA 0183 input/output pairs, one pair can be configured at 4800 and the other at 38400.

Henry

 

[bmac]

Joe, do you have Sal Alfano's phone number? He's the local LI RM factory expert and can talk you through it.

 

[Alex F]

Here's what connections E-series has:



As I understand, according to this diagram, there's no need for multiplexer if connecting AIS receiver. NMEA0183 port is there to make the connection (see bottom right corner).



I could be wrong, but I remember when I was installing weather module I was told that I might need multiplexer. I ended up connecting it all without it.

 

[Alex F]

More info from the manual:

 

[Havana Shamrock]

I have a call into Icom support, Alex as I understand it you can't just connect more than 1 NMEA 0183 devices together. The NMEA port on my E120 is wired to the autopilot, I tried to tie then together but nothing . And the AIS receiver runs at a different Baud rate. So now I'm really confused. if anything I will call Sal.


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[Alex F]

... The NMEA port on my E120 is wired to the autopilot...

Ah, that's the key link that we've been missing. Now that we know your NMEA 0183 port is used for AP it makes things a bit different.

My advice, before making calls and/or spending any money, have a good look and find all the components you currently have. Make the diagram and try to understand how those components are integrated (via 0183 or SeaTalk or 2K). There always can be a chance to reconnect your AP via Seatalk to free up the 0183 port on the MFD.

So, just take a step back and make the diagram. A picture is worth 1000 words, everything will become much clearer for you.

 

[Havana Shamrock]

Ok, so RM tech says I need a multiplexer . It will convert all baud rates. He recommended the actisense NDC-4 he also stated "some" Icom radios have a built in multiplexer. FYI. Thanks for the advice again guys

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[Alex F]

Joe,

I just confirmed my theory with my AP ST7001+. If your is the same I think you can avoid the MP purchase. Mine is connected via SeaTalk.

From the Manual:
Extended systems

You can connect the ST7001+ to other Raymarine SeaTalk
equipment so it can send and receive SeaTalk data:
• it can use wind information from a SeaTalk wind instrument for
Wind Vane steering
• it can use waypoint information from a SeaTalk navigation
instrument to provide track control
• it can use boat speed from a SeaTalk speed instrument to optimize
track-keeping performance


You can also use the ST7001+ autopilot with any navigator
(GPS, Decca, Loran) or wind instrument that transmits National
Marine Electronics Association (NMEA) 0183 data.
The ST7001+ can display SeaTalk and NMEA instrument data in a
user-defined selection of data pages. When you are using the
ST7001+ to repeat instrument data, it shows a ‘pop-up’ pilot page for
5 seconds whenever you make a change in autopilot control.


If you have the manual, look at the section 5.3 (page 50 and 51). It has very detailed and easy explanation on how to connect AP via SeaTalk.